diff --git a/servers/cu/src/app.js b/servers/cu/src/app.js
index acc6a3f04..6cc1faf28 100644
--- a/servers/cu/src/app.js
+++ b/servers/cu/src/app.js
@@ -30,6 +30,7 @@ export const server = pipeP(
      */
     const server = app.listen({ port: config.port, host: '0.0.0.0' }, () => {
       logger(`Server is running on http://localhost:${config.port}`)
+      logger(`Server in unit mode: "${config.UNIT_MODE}"`)
     })
 
     const memMonitor = setInterval(async () => {
diff --git a/servers/cu/src/bootstrap.js b/servers/cu/src/bootstrap.js
index 2f69061b4..268366960 100644
--- a/servers/cu/src/bootstrap.js
+++ b/servers/cu/src/bootstrap.js
@@ -101,7 +101,8 @@ export const createApis = async (ctx) => {
           id: workerId,
           MODE: ctx.MODE,
           LOG_CONFIG_PATH: ctx.LOG_CONFIG_PATH,
-          DEFAULT_LOG_LEVEL: ctx.DEFAULT_LOG_LEVEL
+          DEFAULT_LOG_LEVEL: ctx.DEFAULT_LOG_LEVEL,
+          DISABLE_PROCESS_EVALUATION_CACHE: ctx.DISABLE_PROCESS_EVALUATION_CACHE
         }
       }
     }
diff --git a/servers/cu/src/config.js b/servers/cu/src/config.js
index 0c6ca8694..67f09d5d4 100644
--- a/servers/cu/src/config.js
+++ b/servers/cu/src/config.js
@@ -41,6 +41,11 @@ const DEFAULT_PROCESS_WASM_MODULE_FORMATS = [
  */
 const serverConfigSchema = domainConfigSchema.extend({
   MODE: z.enum(['development', 'production']),
+  /**
+   * Whether the unit is operating as a Compute Unit
+   * or Read Unit. Defaults to 'cu'.
+   */
+  UNIT_MODE: z.enum(['cu', 'ru']),
   port: positiveIntSchema,
   ENABLE_METRICS_ENDPOINT: z.preprocess((val) => !!val, z.boolean())
 })
@@ -51,13 +56,32 @@ const serverConfigSchema = domainConfigSchema.extend({
  */
 /* eslint-disable no-throw-literal */
 
+const preprocessUnitMode = (envConfig) => {
+  const { UNIT_MODE } = envConfig
+
+  if (UNIT_MODE === 'cu') return envConfig
+
+  /**
+   * A Read Unit's primary concern is serving dry-runs,
+   * and so does not create checkpoints and does not cache evaluation
+   * results to be served later.
+   */
+  return {
+    ...envConfig,
+    DISABLE_PROCESS_EVALUATION_CACHE: true,
+    DISABLE_PROCESS_CHECKPOINT_CREATION: true,
+    DISABLE_PROCESS_FILE_CHECKPOINT_CREATION: true,
+    PROCESS_MEMORY_CACHE_CHECKPOINT_INTERVAL: 0
+  }
+}
+
 /**
  * If the WALLET is defined, then do nothing.
  *
  * Otherwise, check whether the WALLET_FILE env var is defined and load it contents
  * as WALLET
  */
-export const preprocessWallet = (envConfig) => {
+const preprocessWallet = (envConfig) => {
   const { WALLET, WALLET_FILE, ...theRestOfTheConfig } = envConfig
 
   //  WALLET takes precendent. nothing to do here
@@ -83,7 +107,7 @@ export const preprocessWallet = (envConfig) => {
 const preprocessedServerConfigSchema = z.preprocess(
   (envConfig, zodRefinementContext) => {
     try {
-      return pipe(preprocessWallet, preprocessUrls)(envConfig)
+      return pipe(preprocessUnitMode, preprocessWallet, preprocessUrls)(envConfig)
     } catch (message) {
       zodRefinementContext.addIssue({ code: ZodIssueCode.custom, message })
     }
@@ -100,6 +124,7 @@ const preprocessedServerConfigSchema = z.preprocess(
 const CONFIG_ENVS = {
   development: {
     MODE,
+    UNIT_MODE: process.env.UNIT_MODE || 'cu',
     DEFAULT_LOG_LEVEL: process.env.DEFAULT_LOG_LEVEL || 'debug',
     LOG_CONFIG_PATH: process.env.LOG_CONFIG_PATH || '.loglevel',
     MODULE_MODE: process.env.MODULE_MODE,
@@ -117,6 +142,7 @@ const CONFIG_ENVS = {
     PROCESS_CHECKPOINT_CREATION_THROTTLE: process.env.PROCESS_CHECKPOINT_CREATION_THROTTLE || ms('30m'),
     DISABLE_PROCESS_CHECKPOINT_CREATION: process.env.DISABLE_PROCESS_CHECKPOINT_CREATION !== 'false',
     DISABLE_PROCESS_FILE_CHECKPOINT_CREATION: process.env.DISABLE_PROCESS_FILE_CHECKPOINT_CREATION !== 'false',
+    DISABLE_PROCESS_EVALUATION_CACHE: process.env.DISABLE_PROCESS_EVALUATION_CACHE,
     /**
      *  EAGER_CHECKPOINT_ACCUMULATED_GAS_THRESHOLD: Amount of gas for 2 hours of continuous compute (300_000_000_000_000)
      *  This was calculated by creating a process built to do continuous compute. After 2 hours, this process used
@@ -149,6 +175,7 @@ const CONFIG_ENVS = {
   },
   production: {
     MODE,
+    UNIT_MODE: process.env.UNIT_MODE || 'cu',
     DEFAULT_LOG_LEVEL: process.env.DEFAULT_LOG_LEVEL || 'debug',
     LOG_CONFIG_PATH: process.env.LOG_CONFIG_PATH || '.loglevel',
     MODULE_MODE: process.env.MODULE_MODE,
@@ -164,8 +191,9 @@ const CONFIG_ENVS = {
     WALLET_FILE: process.env.WALLET_FILE,
     MEM_MONITOR_INTERVAL: process.env.MEM_MONITOR_INTERVAL || ms('30s'),
     PROCESS_CHECKPOINT_CREATION_THROTTLE: process.env.PROCESS_CHECKPOINT_CREATION_THROTTLE || ms('30m'),
-    DISABLE_PROCESS_CHECKPOINT_CREATION: process.env.DISABLE_PROCESS_CHECKPOINT_CREATION !== 'false', // TODO: disabled by default for now. Enable by default later
+    DISABLE_PROCESS_CHECKPOINT_CREATION: process.env.DISABLE_PROCESS_CHECKPOINT_CREATION !== 'false',
     DISABLE_PROCESS_FILE_CHECKPOINT_CREATION: process.env.DISABLE_PROCESS_FILE_CHECKPOINT_CREATION !== 'false',
+    DISABLE_PROCESS_EVALUATION_CACHE: process.env.DISABLE_PROCESS_EVALUATION_CACHE,
     /**
      *  EAGER_CHECKPOINT_ACCUMULATED_GAS_THRESHOLD: Amount of gas for 2 hours of continuous compute (300_000_000_000_000)
      *  This was calculated by creating a process built to do continuous compute by adding and clearing a table.
diff --git a/servers/cu/src/domain/lib/loadMessages.js b/servers/cu/src/domain/lib/loadMessages.js
index c6ae74009..ebb3485a4 100644
--- a/servers/cu/src/domain/lib/loadMessages.js
+++ b/servers/cu/src/domain/lib/loadMessages.js
@@ -369,7 +369,7 @@ function reconcileBlocksWith ({ loadBlocksMeta, findBlocks, saveBlocks }) {
   }
 }
 
-export function maybePrependProcessMessage (ctx, logger) {
+export function maybePrependProcessMessage (ctx, logger, loadTransactionData) {
   return async function * ($messages) {
     const isColdStart = isNil(ctx.from)
 
@@ -405,6 +405,15 @@ export function maybePrependProcessMessage (ctx, logger) {
        */
       if (done || (parseTags(value.message.Tags).Type !== 'Process') || value.message.Cron) {
         logger('Emitting process message at beginning of evaluation stream for process %s cold start', ctx.id)
+
+        /**
+         * data for a process can potentially be very large, and it's only needed
+         * as part of the very first process message sent to the process (aka. Bootloader).
+         *
+         * So in lieu of caching the process data, we fetch it once here, on cold start,
+         */
+        const processData = await loadTransactionData(ctx.id).then(res => res.text())
+
         yield {
           /**
            * Ensure the noSave flag is set, so evaluation does not persist
@@ -416,7 +425,7 @@ export function maybePrependProcessMessage (ctx, logger) {
           message: {
             Id: ctx.id,
             Signature: ctx.signature,
-            Data: ctx.data,
+            Data: processData,
             Owner: ctx.owner,
             /**
              * the target of the process message is itself
@@ -484,7 +493,7 @@ function loadScheduledMessagesWith ({ loadMessages, logger }) {
       )
 }
 
-function loadCronMessagesWith ({ loadTimestamp, findBlocks, loadBlocksMeta, saveBlocks, logger }) {
+function loadCronMessagesWith ({ loadTimestamp, findBlocks, loadBlocksMeta, loadTransactionData, saveBlocks, logger }) {
   loadTimestamp = fromPromise(loadTimestampSchema.implement(loadTimestamp))
 
   const reconcileBlocks = reconcileBlocksWith({ findBlocks, loadBlocksMeta, saveBlocks })
@@ -697,7 +706,7 @@ function loadCronMessagesWith ({ loadTimestamp, findBlocks, loadBlocksMeta, save
     .map($messages => {
       return composeStreams(
         $messages,
-        Transform.from(maybePrependProcessMessage(ctx, logger))
+        Transform.from(maybePrependProcessMessage(ctx, logger, loadTransactionData))
       )
     })
     .map(messages => ({ messages }))
diff --git a/servers/cu/src/domain/lib/loadMessages.test.js b/servers/cu/src/domain/lib/loadMessages.test.js
index 8c92542e2..d9210edc4 100644
--- a/servers/cu/src/domain/lib/loadMessages.test.js
+++ b/servers/cu/src/domain/lib/loadMessages.test.js
@@ -475,6 +475,11 @@ describe('loadMessages', () => {
       }
     }
 
+    const loadTransactionData = async (id) => {
+      assert.equal(id, 'process-123')
+      return new Response('process data')
+    }
+
     describe('should prepend the process message on cold start', () => {
       test('if first stream message is not the process', async () => {
         const $messages = Readable.from([
@@ -486,13 +491,14 @@ describe('loadMessages', () => {
             }
           }
         ])
-        const $merged = maybePrependProcessMessage(ctx, logger)($messages)
+        const $merged = maybePrependProcessMessage(ctx, logger, loadTransactionData)($messages)
 
         const results = []
         for await (const m of $merged) results.push(m)
 
         assert.equal(results.length, 2)
         assert.equal(results[0].name, 'Process Message process-123')
+        assert.equal(results[0].message.Data, 'process data')
       })
 
       test('if the first stream message is a cron message', async () => {
@@ -506,24 +512,26 @@ describe('loadMessages', () => {
             }
           }
         ])
-        const $merged = maybePrependProcessMessage(ctx, logger)($messages)
+        const $merged = maybePrependProcessMessage(ctx, logger, loadTransactionData)($messages)
 
         const results = []
         for await (const m of $merged) results.push(m)
 
         assert.equal(results.length, 2)
         assert.equal(results[0].name, 'Process Message process-123')
+        assert.equal(results[0].message.Data, 'process data')
       })
 
       test('if there are no messages', async () => {
         const $messages = Readable.from([])
-        const $merged = maybePrependProcessMessage(ctx, logger)($messages)
+        const $merged = maybePrependProcessMessage(ctx, logger, loadTransactionData)($messages)
 
         const results = []
         for await (const m of $merged) results.push(m)
 
         assert.equal(results.length, 1)
         assert.equal(results[0].name, 'Process Message process-123')
+        assert.equal(results[0].message.Data, 'process data')
       })
     })
 
@@ -546,7 +554,7 @@ describe('loadMessages', () => {
           }
         }
       ])
-      const $merged = maybePrependProcessMessage(ctx, logger)($messages)
+      const $merged = maybePrependProcessMessage(ctx, logger, loadTransactionData)($messages)
 
       const results = []
       for await (const m of $merged) results.push(m)
diff --git a/servers/cu/src/domain/model.js b/servers/cu/src/domain/model.js
index 3271e743a..d7ed87371 100644
--- a/servers/cu/src/domain/model.js
+++ b/servers/cu/src/domain/model.js
@@ -96,6 +96,11 @@ export const domainConfigSchema = z.object({
    * Whether to disable File Process Checkpoint creation entirely.
    */
   DISABLE_PROCESS_FILE_CHECKPOINT_CREATION: z.preprocess((val) => !!val, z.boolean()),
+  /**
+   * Whether to disable caching process evaluations, useful when operating as
+   * a RU
+   */
+  DISABLE_PROCESS_EVALUATION_CACHE: z.preprocess((val) => !!val, z.boolean()),
   /**
    * If a process uses this amount of
    * gas, then it will immediately create a Checkpoint at the end of the
diff --git a/servers/cu/src/effects/ao-evaluation.js b/servers/cu/src/effects/ao-evaluation.js
index 33bcd94c1..d6ef1eec7 100644
--- a/servers/cu/src/effects/ao-evaluation.js
+++ b/servers/cu/src/effects/ao-evaluation.js
@@ -96,7 +96,7 @@ export function findEvaluationWith ({ db }) {
   }
 }
 
-export function saveEvaluationWith ({ db, logger: _logger }) {
+export function saveEvaluationWith ({ DISABLE_PROCESS_EVALUATION_CACHE, db, logger: _logger }) {
   const toEvaluationDoc = pipe(
     converge(
       unapply(mergeAll),
@@ -138,8 +138,10 @@ export function saveEvaluationWith ({ db, logger: _logger }) {
 
   function createQuery (evaluation) {
     const evalDoc = toEvaluationDoc(evaluation)
-    const statements = [
-      {
+    const statements = []
+
+    if (!DISABLE_PROCESS_EVALUATION_CACHE) {
+      statements.push({
         sql: `
           INSERT OR IGNORE INTO ${EVALUATIONS_TABLE}
             (id, "processId", "messageId", "deepHash", nonce, epoch, timestamp, ordinate, "blockHeight", cron, "evaluatedAt", output)
@@ -160,8 +162,8 @@ export function saveEvaluationWith ({ db, logger: _logger }) {
           evalDoc.evaluatedAt.getTime(),
           JSON.stringify(evalDoc.output)
         ]
-      }
-    ]
+      })
+    }
 
     /**
       * Cron messages are not needed to be saved in the messages table
diff --git a/servers/cu/src/effects/ao-evaluation.test.js b/servers/cu/src/effects/ao-evaluation.test.js
index d9902e5de..925c24e34 100644
--- a/servers/cu/src/effects/ao-evaluation.test.js
+++ b/servers/cu/src/effects/ao-evaluation.test.js
@@ -249,6 +249,38 @@ describe('ao-evaluation', () => {
         evaluatedAt
       })
     })
+
+    test('noop insert evaluation if DISABLE_PROCESS_EVALUATION_CACHE', async () => {
+      const saveEvaluation = saveEvaluationSchema.implement(
+        saveEvaluationWith({
+          DISABLE_PROCESS_EVALUATION_CACHE: true,
+          db: {
+            transaction: async (statements) => {
+              assert.equal(statements.length, 1)
+              const [{ sql: messageDocSql }] = statements
+              assert.ok(messageDocSql.trim().startsWith(`INSERT OR IGNORE INTO ${MESSAGES_TABLE}`))
+
+              return Promise.resolve('process-123,1702677252111,1')
+            }
+          },
+          logger
+        })
+      )
+
+      await saveEvaluation({
+        isAssignment: false,
+        deepHash: 'deepHash-123',
+        timestamp: 1702677252111,
+        nonce: '1',
+        epoch: 0,
+        ordinate: 1,
+        blockHeight: 1234,
+        processId: 'process-123',
+        messageId: 'message-123',
+        output: { Messages: [{ foo: 'bar' }], Memory: 'foo' },
+        evaluatedAt
+      })
+    })
   })
 
   describe('findEvaluations', () => {
diff --git a/servers/cu/src/effects/ao-process.js b/servers/cu/src/effects/ao-process.js
index ec6a9dfad..ff4c13692 100644
--- a/servers/cu/src/effects/ao-process.js
+++ b/servers/cu/src/effects/ao-process.js
@@ -419,6 +419,13 @@ export function saveProcessWith ({ db }) {
   }
   return (process) => {
     return of(process)
+      /**
+       * The data for the process could be very large, so we do not persist
+       * it, and instead hydrate it on the process message later, if needed.
+       */
+      .map(evolve({
+        data: () => null
+      }))
       /**
        * Ensure the expected shape before writing to the db
        */
diff --git a/servers/cu/src/effects/ao-process.test.js b/servers/cu/src/effects/ao-process.test.js
index 301af9c9d..278299f29 100644
--- a/servers/cu/src/effects/ao-process.test.js
+++ b/servers/cu/src/effects/ao-process.test.js
@@ -134,7 +134,7 @@ describe('ao-process', () => {
               assert.deepStrictEqual(parameters, [
                 'process-123',
                 'sig-123',
-                'data-123',
+                null, // data is nullified
                 null,
                 JSON.stringify({ address: 'owner-123', key: 'key-123' }),
                 JSON.stringify([{ name: 'foo', value: 'bar' }]),
diff --git a/servers/cu/src/effects/worker/evaluator/main.js b/servers/cu/src/effects/worker/evaluator/main.js
index 69fec8d48..ed01449bc 100644
--- a/servers/cu/src/effects/worker/evaluator/main.js
+++ b/servers/cu/src/effects/worker/evaluator/main.js
@@ -18,7 +18,11 @@ export const createApis = async (ctx) => {
       CHECKPOINT_GRAPHQL_URL: ctx.CHECKPOINT_GRAPHQL_URL
     }),
     bootstrapWasmInstance: WasmClient.bootstrapWasmInstanceWith(),
-    saveEvaluation: AoEvaluationClient.saveEvaluationWith({ db, logger: ctx.logger }),
+    saveEvaluation: AoEvaluationClient.saveEvaluationWith({
+      DISABLE_PROCESS_EVALUATION_CACHE: ctx.DISABLE_PROCESS_EVALUATION_CACHE,
+      db,
+      logger: ctx.logger
+    }),
     ARWEAVE_URL: ctx.ARWEAVE_URL,
     logger: ctx.logger
   })
diff --git a/servers/cu/src/routes/cron.js b/servers/cu/src/routes/cron.js
index 9a5f49ab9..f79be4b2d 100644
--- a/servers/cu/src/routes/cron.js
+++ b/servers/cu/src/routes/cron.js
@@ -2,6 +2,7 @@ import { always, compose, identity } from 'ramda'
 import { z } from 'zod'
 
 import { withMetrics, withMiddleware, withProcessRestrictionFromPath } from './middleware/index.js'
+import { withCuMode } from './middleware/withCuMode.js'
 
 /**
  * TODO: could be moved into a route utils or middleware
@@ -37,8 +38,9 @@ export const withCronRoutes = app => {
     '/cron/:processId',
     compose(
       withMiddleware,
-      withMetrics({ tracesFrom: (req) => ({ process_id: req.params.processId }) }),
+      withCuMode,
       withProcessRestrictionFromPath,
+      withMetrics({ tracesFrom: (req) => ({ process_id: req.params.processId }) }),
       always(async (req, res) => {
         const {
           params: { processId },
diff --git a/servers/cu/src/routes/middleware/index.js b/servers/cu/src/routes/middleware/index.js
index 08e0c9836..a31853bf8 100644
--- a/servers/cu/src/routes/middleware/index.js
+++ b/servers/cu/src/routes/middleware/index.js
@@ -5,6 +5,7 @@ import { withDomain } from './withDomain.js'
 
 export * from './withProcessRestriction.js'
 export * from './withMetrics.js'
+export * from './withCuMode.js'
 
 /**
  * A convenience method that composes common middleware needed on most routes,
diff --git a/servers/cu/src/routes/middleware/withCuMode.js b/servers/cu/src/routes/middleware/withCuMode.js
new file mode 100644
index 000000000..001d4f845
--- /dev/null
+++ b/servers/cu/src/routes/middleware/withCuMode.js
@@ -0,0 +1,12 @@
+import { config } from '../../config.js'
+
+const withUnitMode = (mode) => (handler) => (req, res, next) => {
+  const { UNIT_MODE } = config
+
+  if (UNIT_MODE !== mode) return res.status(404).send('Not Found')
+
+  return handler(req, res, next)
+}
+
+export const withCuMode = withUnitMode('cu')
+export const withRuMode = withUnitMode('ru')
diff --git a/servers/cu/src/routes/result.js b/servers/cu/src/routes/result.js
index 371a5f20e..d946ce289 100644
--- a/servers/cu/src/routes/result.js
+++ b/servers/cu/src/routes/result.js
@@ -2,7 +2,7 @@ import { compose } from 'ramda'
 import { z } from 'zod'
 
 import { busyIn } from '../domain/utils.js'
-import { withMetrics, withMiddleware, withProcessRestrictionFromQuery } from './middleware/index.js'
+import { withMetrics, withMiddleware, withProcessRestrictionFromQuery, withCuMode } from './middleware/index.js'
 import { withInMemoryCache } from './middleware/withInMemoryCache.js'
 
 const inputSchema = z.object({
@@ -15,8 +15,9 @@ export const withResultRoutes = app => {
     '/result/:messageTxId',
     compose(
       withMiddleware,
-      withMetrics({ tracesFrom: (req) => ({ process_id: req.query['process-id'] }) }),
+      withCuMode,
       withProcessRestrictionFromQuery,
+      withMetrics({ tracesFrom: (req) => ({ process_id: req.query['process-id'] }) }),
       withInMemoryCache({
         keyer: (req) => {
           const { params: { messageTxId } } = req
diff --git a/servers/cu/src/routes/results.js b/servers/cu/src/routes/results.js
index ae4c81dbd..9f5a8d456 100644
--- a/servers/cu/src/routes/results.js
+++ b/servers/cu/src/routes/results.js
@@ -1,8 +1,8 @@
 import { always, compose, identity } from 'ramda'
-
-import { withMetrics, withMiddleware, withProcessRestrictionFromPath } from './middleware/index.js'
 import { z } from 'zod'
 
+import { withMetrics, withMiddleware, withProcessRestrictionFromPath, withCuMode } from './middleware/index.js'
+
 /**
  * TODO: could be moved into a route utils or middleware
  *
@@ -47,8 +47,9 @@ export const withResultsRoutes = app => {
     '/results/:processId',
     compose(
       withMiddleware,
-      withMetrics({ tracesFrom: (req) => ({ process_id: req.params.processId }) }),
+      withCuMode,
       withProcessRestrictionFromPath,
+      withMetrics({ tracesFrom: (req) => ({ process_id: req.params.processId }) }),
       always(async (req, res) => {
         const {
           params: { processId },
diff --git a/servers/cu/src/routes/state.js b/servers/cu/src/routes/state.js
index f6ac2f2ba..fe8ffb853 100644
--- a/servers/cu/src/routes/state.js
+++ b/servers/cu/src/routes/state.js
@@ -2,7 +2,7 @@ import { always, compose } from 'ramda'
 import { z } from 'zod'
 
 import { arrayBufferFromMaybeView, busyIn } from '../domain/utils.js'
-import { withMetrics, withMiddleware, withProcessRestrictionFromPath } from './middleware/index.js'
+import { withMetrics, withMiddleware, withProcessRestrictionFromPath, withCuMode } from './middleware/index.js'
 
 const inputSchema = z.object({
   processId: z.string().min(1, 'an ao process id is required'),
@@ -15,8 +15,9 @@ export const withStateRoutes = (app) => {
     '/state/:processId',
     compose(
       withMiddleware,
-      withMetrics({ tracesFrom: (req) => ({ process_id: req.params.processId }) }),
+      withCuMode,
       withProcessRestrictionFromPath,
+      withMetrics({ tracesFrom: (req) => ({ process_id: req.params.processId }) }),
       always(async (req, res) => {
         const {
           params: { processId },